Question:
Which PID term depends on past accumulated error?
Options:
A) Integral
B) Proportional
C) Derivative
D) Bias
View Answer
Correct Answer: A) Integral
Detailed Explanation
The Integral (I) term depends on the accumulated error over time.
Mathematically:
This means the controller continuously sums past error values. If error persists, the integral term keeps increasing until the steady-state deviation becomes zero.
Why This Is Important
Integral action:
- Eliminates steady-state offset
- Corrects small but persistent errors
- Provides long-term accuracy
Without integral action, some error would remain in steady state.
Why Other Options Are Incorrect
B) Proportional → Depends only on present error.
C) Derivative → Depends on rate of change of error.
D) Bias → Is a fixed baseline value, not related to accumulated error.